Bugs or crabs that infest the nether regions of people that have seriously bad hygene whether they be male or female.
Children, especially unpleasant ones.
Oh, no, here come the Breedersons and their ill-behaved litter of crotch critters again.
Things or living organisms living and/or growing within a females genitals that can induce a nasty smell or disgusting look to the pussy.
You'd better avoid fucking her, she's got some nasty crotch critters and you don't want to catch them!
Any other living thing that does not belong in the genital area.
The girl I slept with gave me crotch critters.
I was going to have sex with her until her crotch critters started dancing